Phased array radars require many individually controllable transmit/receive modules (hereinafter T/R modules) arranged in an array of N.times.M modules. Each T/R module includes microwave signal processing means comprising a number of microwave or RF frequency processing components for processing radar signals; control signal processing means comprising a number of signal processing components selectively interconnected with the microwave signal processing components for providing control signals thereto; and power conditioning means comprising a number of power conditioning components selectively interconnected with the microwave signal processing components and the control signal processing components for providing power thereto. Also, because the phased array radars operate at relatively high power levels, there is usually provided means for cooling the various components, especially the microwave signal processing components and the power conditioning components.
Phased array radars may require as many as 2000 T/R modules, each measuring as much as 6 inches on a side and being several inches thick and dissipating many watts of power. The cost of each module may be many thousands of dollars. The relatively large size of each module adds considerably to the cost because there are many lead connections which must be individually made and each connection (especially at microwave frequencies) must be optimally designed to reduce noise loses and side lobes.
In so-called monolithic microwave integrated circuits (MMIC's) the fabrication of microwave components, whether active or passive, and their interconnections onto a single substrate has been proposed by Stockton et al. in U.S. Pat. No. 4,490,721. However, a MMIC as shown in Stockton et al. does not integrate on a substrate various functional technologies including microwave, power conditioning, control, memory and heat management. Furthermore, Stockton et al. relies on thin film techniques and IC fabrication techniques which normally have very low yields, especially when the various elements are distributed over a relatively large substrate area. Thus, although miniaturization is desirable because performance and cost are usually dramatically improved, the arrangement disclosed by Stockton et al. has some serious shortcomings.
A multi-layer package for Large Scale Integration (LSI) chips and a method of testing and inspecting such a package has been described by Zingher in U.S. Pat. No. 4,578,279. However, the package is not useful for microwave applications because it has no provision for mounting and cooling microwave and power circuits.